From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F0726CD54BF for ; Mon, 25 Sep 2023 20:11:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233276AbjIYULq convert rfc822-to-8bit (ORCPT ); Mon, 25 Sep 2023 16:11:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229481AbjIYULo (ORCPT ); Mon, 25 Sep 2023 16:11:44 -0400 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 431519B for ; Mon, 25 Sep 2023 13:11:38 -0700 (PDT) Received: from imladris.home.surriel.com ([10.0.13.28] helo=imladris.surriel.com) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qkrvU-00065u-2H; Mon, 25 Sep 2023 16:11:28 -0400 Message-ID: <2813e3aea98da510b9075e2a532272a1f77f5355.camel@surriel.com> Subject: Re: [PATCH 3/3] hugetlbfs: replace hugetlb_vma_lock with invalidate_lock From: Rik van Riel To: Mike Kravetz Cc: kernel test robot , linux-kernel@vger.kernel.org, oe-kbuild-all@lists.linux.dev, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, muchun.song@linux.dev, leit@meta.com, willy@infradead.org Date: Mon, 25 Sep 2023 16:11:28 -0400 In-Reply-To: <20230925200659.GB11309@monkey> References: <20230922190552.3963067-4-riel@surriel.com> <202309250923.NEPT0ip2-lkp@intel.com> <692fafae9842a9b15b7b4a033bb7dc800784d4aa.camel@surriel.com> <20230925200659.GB11309@monkey> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.46.4 (3.46.4-1.fc37) MIME-Version: 1.0 Sender: riel@surriel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2023-09-25 at 13:06 -0700, Mike Kravetz wrote: > On 09/25/23 15:22, Rik van Riel wrote: > > On Mon, 2023-09-25 at 10:04 +0800, kernel test robot wrote: > > > Hi, > > > > > > kernel test robot noticed the following build errors: > > > > > > [auto build test ERROR on akpm-mm/mm-everything] > > > [also build test ERROR on linus/master v6.6-rc3 next-20230921] > > > [If your patch is applied to the wrong git tree, kindly drop us a > > > note. > > > And when submitting patch, we suggest to use '--base' as > > > documented > > > in > > > https://git-scm.com/docs/git-format-patch#_base_tree_information] > > > > OK, so I have a fix for patch 3/3 that gets rid of the > > compile error, but the libhugetlbfs test cases show that > > patch 3/3 opens up a condition where resv_hugepages > > underflows. > > > > I have not figured out the cause of that yet, but > > patches 1 & 2 seem to survive all tests fine. > > In addition, I suspect patch 3 is going to cause a performance > regression. > It is taking me a little while to resurrect the test environment used > when > the hugetlb vma lock was introduced.  My plan is to exercise the > series in > that environment. > I am planning to send a v3 of the series soon, once I have confirmed that the bugs in patch 3 have all been fixed. I have no strong opinion on whether or not patch 3 gets merged at all. Patches 1 & 2 fix the actual bug that I am trying to fix, and I am perfectly fine if patch 3 ends up getting dropped in the end. It seemed worth trying to get that cleanup though ;) > I should be able to review patches 1 & 2 later (my) today. Thank you! -- All Rights Reversed.